pthread_cond_destroy(3t) [hpux man page]

pthread_cond_init(3T)													     pthread_cond_init(3T)

NAME

       pthread_cond_init(), pthread_cond_destroy() - initialize or destroy a condition variable

SYNOPSIS

PARAMETERS

	      cond	Pointer to the condition variable to be initialized or destroyed.

	      attr	Pointer  to  the  attributes  object that defines the characteristics of the condition variable to be initialized.  If the
			pointer is NULL, default attributes are used.

DESCRIPTION

       The function initializes the condition variable cond with the attributes attr.  If attr is NULL, the default condition variable	attributes
       are  used  to  initialize  the  attributes  object.  See pthread_condattr_init(3T) for a list of the default condition variable attributes.
       After successful initialization, the condition variable may be used in condition variable operations.  A condition variable should be  ini-
       tialized  only  once  or the resulting behavior is undefined.  The function provides a way to ensure that a condition variable is only ini-
       tialized once.

       The macro can be used to initialize condition variables that are statically allocated.  These condition variables will be initialized  with
       default attributes.  The function does not need to be called for statically initialized condition variables.

       If the process-shared attribute in the condition variable attributes object referenced by attr is defined as the condition variable must be
       allocated such that the processes sharing the condition variable have access to it.  This may be done through the memory-mapping  functions
       (see mmap(2)) or the shared memory functions (see shmget(2)).

       destroys  the condition variable cond.  This function may set cond to an invalid value.	The destroyed condition variable can be reinitial-
       ized using the function If the condition variable is used after destruction in any condition variable call, the resulting behavior is unde-
       fined.

       A  condition  variable should be destroyed only when there are no threads currently blocked on it.  Destroying a condition variable that is
       currently in use results in undefined behavior.

RETURN VALUE

       Upon successful completion, and return zero.  Otherwise, an error number is returned to indicate the error (the variable is not set).

ERRORS

       If any of the following occur, the function returns the corresponding error number:

	      The system does not have the available resources (other than memory)
			     to initialize the condition variable.

	      The specified condition variable is an already initialized condition
			     variable.	However, getting for reinitializing the condition variable cannot be  expected	all  the  time	since  the
			     behavior of reinitializing the condition variable is undefined.

	      The	     cond parameter points to an illegal address.

	      The value specified by
			     cond or attr is invalid.

	      There is insufficient memory available in which to initialize
			     the condition variable.

       If any of the following occur, the function returns the corresponding error number:

	      An attempt to destroy
			     cond while it is in use by another thread.

	      cond	     is not a valid condition variable.

WARNINGS

       The space for condition variable must be allocated before calling Undefined behavior will result if the process-shared attribute of attr is
       and the space allocated for the condition variable is not accessible to cooperating threads.

AUTHOR

       and were derived from the IEEE POSIX P1003.1c standard.

SEE ALSO

       pthread_cond_signal(3T), pthread_cond_wait(3T).

STANDARDS CONFORMANCE

								  Pthread Library					     pthread_cond_init(3T)

pthread_cond_init(3C)					   Standard C Library Functions 				     pthread_cond_init(3C)

NAME

       pthread_cond_init, pthread_cond_destroy - initialize or destroy condition variables

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_cond_init(pthread_cond_t *restrict cond,
	    const pthread_condattr_t *restrict attr);

       int pthread_cond_destroy(pthread_cond_t *cond

       pthread_cond_t cond= PTHREAD_COND_INITIALIZER;

DESCRIPTION

       The  function  pthread_cond_init()  initializes	the  condition	variable referenced by cond with attributes referenced by attr. If attr is
       NULL, the default condition variable attributes are used; the effect is the same as passing the address of  a  default  condition  variable
       attributes object. See pthread_condattr_init(3C). Upon successful initialization, the state of the condition variable becomes initialized.

       Attempting to initialize an already initialized condition variable results in undefined behavior.

       The  function pthread_cond_destroy() destroys the given condition variable specified by cond; the object becomes, in effect, uninitialized.
       An implementation may cause pthread_cond_destroy() to set the object referenced by cond to an invalid value. A destroyed condition variable
       object  can  be	re-initialized	using pthread_cond_init(); the results of otherwise referencing the object after it has been destroyed are
       undefined.

       It is safe to destroy an initialized condition variable upon which no threads are currently blocked.  Attempting  to  destroy  a  condition
       variable upon which other threads are currently blocked results in undefined behavior.

       In  cases where default condition variable attributes are appropriate, the macro  PTHREAD_COND_INITIALIZER can be used to initialize condi-
       tion variables that are statically allocated. The effect is equivalent to dynamic initialization by  a  call  to  pthread_cond_init()  with
       parameter attr specified as  NULL, except that no error checks are performed.

RETURN VALUES

       If  successful,	the pthread_cond_init() and pthread_cond_destroy() functions return  0. Otherwise, an error number is returned to indicate
       the error. The EBUSY and EINVAL error checks, if implemented, act as if they were performed immediately at the beginning of processing  for
       the function and caused an error return prior to modifying the state of the condition variable specified by cond.

ERRORS

       The  pthread_cond_init() function will fail if:

       EAGAIN	 The system lacked the necessary resources (other than memory) to initialize another condition variable.

       ENOMEM	 Insufficient memory exists to initialize the condition variable.

       The pthread_cond_init() function may fail if:

       EBUSY	 The  implementation has detected an attempt to re-initialize the object referenced by cond, a previously initialized, but not yet
		 destroyed, condition variable.

       EINVAL	 The value specified by attr is invalid.

       The pthread_cond_destroy() function may fail if:

       EBUSY	 The implementation has detected an attempt to destroy the object referenced by cond while it is referenced  (for  example,  while
		 being used in a pthread_cond_wait() or pthread_cond_timedwait()) by another thread.

       EINVAL	 The value specified by cond is invalid.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       pthread_cond_signal(3C),    pthread_cond_broadcast(3C),	 pthread_cond_wait(3C),   pthread_cond_timedwait(3C),	pthread_condattr_init(3C),
       attributes(5), condition(5), standards(5)

SunOS 5.11							    23 Mar 2005 					     pthread_cond_init(3C)